Refactor the Java AppBannerManager to be owned by native code.

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
index b168c932c13076965547540bdaf3e825c40061ae..1c73129262b33c3ed86c7a4b120c6896d69eaba6 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
@@ -180,9 +180,6 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
     /** InfoBar container to show InfoBars for this tab. */
     private InfoBarContainer mInfoBarContainer;
 
-    /** Manages app banners shown for this tab. */
-    private AppBannerManager mAppBannerManager;
-
     /** Controls overscroll pull-to-refresh behavior for this tab. */
     private SwipeRefreshHandler mSwipeRefreshHandler;
 
@@ -1435,11 +1432,6 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
 
             RevenueStats.getInstance().tabCreated(this);
 
-            if (AppBannerManager.isEnabled()) {
-                mAppBannerManager = mDelegateFactory.createAppBannerManager(this);
-                if (mAppBannerManager != null) addObserver(mAppBannerManager);
-            }
-
             mTopControlsVisibilityDelegate =
                     mDelegateFactory.createTopControlsVisibilityDelegate(this);
 
@@ -1472,6 +1464,8 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
                 didStartPageLoad(webContents.getUrl(), false);
             }
         } finally {
+            AppBannerManager.setIsEnabled(mDelegateFactory.allowAppBanners(this));

[gone, 2016/07/07 20:41:14]

Eh, why is this here?  The only reason the ugly try/finally block exists is to
handle timestamps.  Also, this breaks banners:
1) Open Chrome as a browser, app banners are globally enabled
2) Open a custom tab via another app, app banners are globally disabled
3) Return to Chrome as a browser, app banners are still globally disabled

[dominickn, 2016/07/08 01:17:53]

Thanks for clarifying. I've split up the enabled check into the static (is
homescreen intent enabled) and per-Manager (per tab)

+
             if (mTimestampMillis == INVALID_TIMESTAMP) {
                 mTimestampMillis = System.currentTimeMillis();
             }
@@ -1561,7 +1555,7 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
                 mWebContentsDelegate, mDelegateFactory.createContextMenuPopulator(this));
         mTopControlsVisibilityDelegate = mDelegateFactory.createTopControlsVisibilityDelegate(this);
         setInterceptNavigationDelegate(mDelegateFactory.createInterceptNavigationDelegate(this));
-        mAppBannerManager = mDelegateFactory.createAppBannerManager(this);
+        AppBannerManager.setIsEnabled(mDelegateFactory.allowAppBanners(this));
 
         // Reload the NativePage (if any), since the old NativePage has a reference to the old
         // activity.
@@ -2031,13 +2025,6 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
             mInfoBarContainer = null;
         }
 
-        // Destroy the AppBannerManager after the InfoBarContainer because it monitors for infobar
-        // removals.
-        if (mAppBannerManager != null) {
-            mAppBannerManager.destroy();
-            mAppBannerManager = null;
-        }
-
         mPreviousFullscreenTopControlsOffsetY = Float.NaN;
         mPreviousFullscreenContentOffsetY = Float.NaN;
 
@@ -2528,13 +2515,6 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
         }
     }
 
-    /** Requests the app banner. This method is called from the DevTools. */
-    protected boolean requestAppBanner() {
-        if (mAppBannerManager == null) return false;
-        mAppBannerManager.requestAppBanner();
-        return true;
-    }
-
     @CalledByNative
     private void clearNativePtr() {
         assert mNativeTabAndroid != 0;
@@ -3005,7 +2985,7 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
      */
     @VisibleForTesting
     public AppBannerManager getAppBannerManagerForTesting() {
-        return mAppBannerManager;
+        return AppBannerManager.getAppBannerManager(getWebContents());
     }
 
     @VisibleForTesting